Do armies still invade by parachute? Wouldn’t it make more sense to just book a flight to Seattle and take the country over, starting with that guy elbowing travelers at the baggage carousel?

Parachutes are more cinematic, I guess. In the early going of “Red Dawn” — the unnecessary, un-fun remake of John Milius’ 1984 Russians-invade-America cult fave — hundreds of CG-rendered North Korean paratroopers descend on Spokane, ready to kill any Americans who get in the way.

Shot more than three years ago and only now making its way to the multiplexes, “Red Dawn is a movie with a Red State state of mind. (The invaders were originally Chinese, but with three years to consider geopolitical trends, the filmmakers wisely changed the bad guys to a nation that oesn’t own a giant U.S. theatrical exhibition chain.) A TV news montage of the world going kablooey — Europe in crisis, cyberhackers shutting down power grids, Asian conflagrations and Middle East attacks, and Obama and Biden and Hillary Clinton trying to calm a nation’s frayed nerves — lets us know that things are not going swimmingly. And then Kim Jong-un’s army arrives.

Luckily, a bunch of defiant Washington teens jump in a pickup truck, crash through some barricades, and make for a cabin in the woods, where they plot a guerrilla campaign against Captain Cho (a villainous Will Yun Lee) and his tanks and armored vehicles.

Well-stocked with guns and ammo, and armed with a good nickname — the Wolverines, after the school football team — the boys make sorties into town to blow up occupied buildings and generally make a patriotic nuisance of themselves.

The resistance fighters are led by Iraq War veteran Jed Eckert (Chris Hemsworth, pre-“Thor) and his smug kid brother, Matt (Josh Peck), the star quarterback. There’s a techie guy (Josh Hutcherson), the mayor’s son (Connor Cruise), a cheerleader (Isabel Lucas), and the girl (Adrianne Palicki) with a crush on Jed. After a while, three ex-Marines show up, too.

The “Red Dawn” reboot, directed by Dan Bradley, a stunt coordinator and second unit director (action! action! action!), is hobbled by a laughably bad script and a uniformly uncharismatic cast. Peck, for one, wouldn’t be convincing if he was filmed sitting on a couch, working his “Call of Duty” game controls.